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Abstract:

A dishwasher includes a rinsing container having a rinsing chamber and a
drying facility which is provided outside of the rinsing container and
fluidically connected to the rinsing chamber for drying air charged with
humidity from the rinsing chamber. A storage tank is fluidically
connectable with the rinsing chamber for intermediately storing rinsing
fluid.

Claims:

1-17. (canceled)

18. A dishwasher, comprising: a rinsing container having a rinsing
chamber; a drying facility provided outside of the rinsing container and
fluidically connected to the rinsing chamber for drying air charged with
humidity from the rinsing chamber; and a storage tank fluidically
connectable with the rinsing chamber for intermediately storing rinsing
fluid.

19. The dishwasher of claim 18, constructed in the form of a domestic
dishwasher.

20. The dishwasher of claim 18, wherein the rinsing container has a
common rinsing container opening for fluidically connecting both the
storage tank and the drying facility to the rinsing chamber.

21. The dishwasher of claim 18, further comprising a fan for guiding in a
drying step during a wash cycle, the air charged with humidity into the
drying facility by way of the common rinsing container opening.

22. The dishwasher of claim 18, wherein the storage tank is filled with
rinsing fluid or emptied in the presence of a pressure balance by way of
the common rinsing container opening.

23. The dishwasher of claim 18, wherein the storage tank is cleaned by
rinsing the storage tank with rinsing fluid, with the rinsing fluid
rinsed through the storage tank being conducted into the rinsing chamber
by way of the common rinsing container opening.

24. The dishwasher of claim 20, further comprising an intake duct
connected between the drying facility and the common rinsing container
opening for conducting air charged with humidity to the drying facility.

25. The dishwasher of claim 24, wherein the intake duct comprises a first
channel segment, which is routed upwards starting from the common rinsing
container opening above a head.

26. The dishwasher of claim 25, wherein the intake duct comprises a
second channel segment which connects to the first channel segment and is
fed downwards in an opposite direction to the first channel segment.

27. The dishwasher of claim 20, further comprising an outlet duct
connecting a storage chamber of the storage tank to the common rinsing
container opening.

28. The dishwasher of claim 27, wherein the outlet duct comprises an
input opening, which is connected to the storage chamber of the storage
tank, and which is arranged above the common rinsing container opening
above a height difference.

29. The dishwasher of claim 28, wherein the input opening is configured
as an overflow opening.

30. The dishwasher of claim 27, wherein the outlet duct and the storage
tank are embodied as a structural unit in at least one of two ways, a
first way in which the outlet duct and the storage tank are composed of a
single material, a second way in which the outlet duct and the storage
tank are embodied in one piece.

31. The dishwasher of claim 30, wherein the outlet duct and the storage
tank are embodied as a plastic injection molded part.

32. The dishwasher of claim 24, wherein the storage tank is arranged
together with the intake duct on a side wall of the rinsing container.

33. The dishwasher of claim 24, wherein at least one of the storage tank
and the intake duct comprises two essentially congruent side walls, which
are fluidically connected to one another by way of peripheral edges.

34. The dishwasher of claim 24, wherein the storage tank and the intake
duct are embodied so as to complement one another.

35. The dishwasher of claim 18, wherein the storage tank has an
essentially L-shaped configuration and includes a first container segment
extended in a depth direction and a second container segment protruding
vertically from the first container segment.

36. The dishwasher of claim 35, wherein the first container segment is
arranged in an area of a floor of the storage tank.

37. The dishwasher of claim 35 further comprising an intake duct
connected between the drying facility and the common rinsing container
opening for conducting air charged with humidity to the drying facility,
said first and second container segments delimiting an installation space
outside of the L-shaped storage tank, in which the intake duct runs.

38. The dishwasher of claim 37, wherein the intake duct has a channel
segment which runs in the installation space and is routed to the common
rinsing container opening.

39. The dishwasher of claim 35, wherein the common rinsing container
opening is arranged on an inner corner region between the first and
second container segments of the storage tank.

40. The dishwasher of claim 37, wherein the first container segment
extends horizontally, said intake duct running past a front face of the
first container segment.

41. The dishwasher of claim 40, wherein the intake duct comprises a first
channel segment, which is routed upwards starting from a common rinsing
container opening of the rinsing chamber for fluidically connecting both
the storage tank and the drying facility to the rinsing chamber, and a
second channel segment routed opposite to the first channel segment.

42. The dishwasher of claim 41, wherein the second channel segment is
routed into an assembly space below the rinsing container.

43. A method for operating a dishwasher, comprising: guiding in a drying
step during a wash cycle air charged with humidity into a drying facility
by way of a common rinsing container opening of a rinsing chamber for
fluidically connecting a storage tank and the drying facility to the
rinsing chamber; guiding in an desorption step during at least one
partial wash cycle, the air out of the rinsing chamber via the common
rinsing container opening into the drying facility for dehumidifying
sorption material in the drying facility; establishing a pressure
balance, when filling or emptying the storage tank, by way of the common
rinsing container opening; and cleaning a storage tank by routing a
rinsing fluid via the common rinsing container opening into the rinsing
chamber.

Description:

[0001] The invention relates to a dishwasher as claimed in the preamble of
claim 1 and to a method for operating such a dishwasher as claimed in
claim 17.

[0002] With dishwashers, reduced energy and time expenditure during the
wash cycle at the same time as a high cleaning performance is of
significant importance.

[0003] DE 10 2005 004 089 A1 discloses a generic dishwasher, with which in
the wash cycle, instead of condensation drying with the aid of an
external drying system, air drying takes place outside of the rinsing
chamber. A sorption column with a reversibly dehydrogenizable material is
provided as the drying facility, said material extracting a quantity of
water from the air to be dried and storing the same. The thus dried air
is then fed back into the rinsing chamber. A drying step which is
shortened in comparison with condensation drying can take place in this
way, accompanied by energy-savings. The dehumidification of the
reversibly dehydrogenizable material of a sorption drying facility of
this type usually takes place by means of an assigned electrical heating
facility, in particular air heater, advantageously during at least one
fluid-conveying partial wash cycle of a selected dishwasher program so
that heated air can be routed from the sorption drying facility into the
rinsing chamber of the dishwasher and can be used there to warm/heat up
washing liquor, thereby being energy-efficient. The component outlay for
the production of the dishwasher nevertheless increases with the
provision of the external drying system.

[0004] The object underlying the invention is to provide a dishwasher and
a method for operating a dishwasher, in particular domestic dishwasher,
the energy and/or water demand of which can be further reduced.

[0005] The object is achieved by the features of claim 1 or of claim 17.

[0006] According to the characterizing portion of claim 1, the dishwasher
also comprises a storage tank in which rinsing fluid can be
intermediately stored during or after running a wash cycle. In this way,
after running one of the partial program steps for instance, like a
rinse-aid step, the rinsing fluid which is no longer needed is
intermediately stored in the storage tank and reused in a subsequent wash
cycle, like the pre-rinse step. The water and/or energy demand during a
wash cycle can therefore be reduced by using the storage tank.

[0007] The storage tank can, like the drying facility too, be fluidically
connected to the rinsing chamber bounded by the rinsing container. The
rinsing container openings for siphoning off the air to be dried into the
drying facility and a rinsing container opening to the storage tank are
therefore needed.

[0008] The embodiment of two rinsing container openings which are separate
from one another is however complicated in terms of manufacture.
Furthermore, each of the openings is to be provided with corresponding
fluid seals, which is technically very complicated. In an advantageous
embodiment of the invention, both the storage tank and also the drying
facility can therefore be fluidically connected to the rinsing chamber by
way of a common rinsing container opening. A further rinsing container
opening can thus be dispensed with. This in particular reduces the
component outlay for the manufacture of the dishwasher, i.e. its
construction is simplified. The common rinsing container opening is
therefore assigned with a dual function both to the storage tank and also
to the drying facility.

[0009] In this way, during the drying step, the air charged with
significant humidity can for instance be conducted via the common rinsing
container opening into the drying facility by means of a fan.

[0010] In addition to or regardless of this, in a desorption step during
at least one fluid-conveying partial wash cycle, air can be guided out of
the rinsing chamber via the common rinsing container opening into the
drying facility in order to dehumidify its sorption material.

[0011] The storage tank can be filled with rinsing fluid in a rinse-aid
step upstream of the drying step in a time-delayed fashion with respect
to said drying step and/or emptied in order to implement the pre-rinse
step. The pressure balance needed when filling or emptying the storage
tank can take place in accordance with the invention by way of the common
rinsing container opening.

[0012] In addition or alternatively, a storage tank cleaning can take
place for instance within the scope of a wash cycle, in which the rinsing
fluid is rinsed through the storage tank at a high temperature and at
high pressure. As a result, fat deposits in the storage tank can be
thermally broken down and guided out of the storage tank. In accordance
with the invention, the cleaning fluid rinsed through the storage tank
can be conducted into the rinsing chamber via the common rinsing
container opening.

[0013] An intake duct can be connected between the external drying
facility and the common rinsing container opening, via which intake duct
the air charged with humidity is guided to the drying facility. In the
intake duct, approximately at its downstream side ahead of the drying
facility, a fan and/or a heating element can be provided in order on the
one hand to guide air out of the rinsing chamber into the drying facility
and on the other hand to heat this, in particular for a desorption
process, i.e. dehumidification of its reversibly dehyrdrogenizable drying
material, such as zeolite for instance.

[0014] As mentioned above, rinsing fluid is rinsed through the storage
tank during the storage tank cleaning, said rinsing fluid entering the
rinsing chamber via the common rinsing container opening. Encroachment of
fluid into the drying facility is to be avoided here, in order in
particular to keep its sorption material functional for a drying step of
a selected dishwasher program. For safety reasons it is therefore
advantageous if the intake duct expediently comprises a channel segment
which is guided upwards above a predetermined head starting from the
common rinsing container opening. The intake duct may also comprise in
particular a second channel segment connected thereto, which is routed
downwards in the opposite direction to the first channel segment. The
channel segment routed upwards above the head advantageously also
provides a condensation path along which humidity can condense during the
drying process, said moisture being fed back into the rinsing chamber in
the fluid phase.

[0015] Similarly, it may be expedient for safety reasons if the storage
chamber of the storage tank does not open directly into the common
rinsing container opening. The storage chamber can therefore preferably
be connected to the common rinsing container opening by way of an outlet
duct.

[0016] The outlet duct expediently comprises an inlet opening which is
connected to the storage chamber of the storage tank, in particular to
the overflow opening of the storage tank. In order to completely exhaust
the storage capacity, the outlet opening of the storage tank, which opens
into the inlet segment of the outlet duct via its inlet opening, can be
arranged in particular in an upper apex of the storage tank. As a result,
a fill level of the fluid to be stored in the storage tank can be applied
up to this apex without the fluid to be stored being able to drain off
into the rinsing chamber by way of the outlet opening and the common
rinsing container opening.

[0017] In the cleaning mode, the rinsing fluid can therefore be pumped
into the storage tank through a fluid inlet and can be fed back into the
rinsing container via the outlet opening of the storage tank and the
outlet duct coupled, in particular molded thereto and the common rinsing
container opening.

[0018] According to an advantageous development of the invention, the
storage tank and/or the intake duct can be easily produced as plastic
components which can in turn be manufactured using an injection molding
method. By way of example, the storage tank or the intake duct may
comprise two essentially congruent opposite side walls. The two opposite
side walls may be fluidically connected to one another by way of a narrow
peripheral edge flange, for instance by means of adhesion or welding.

[0019] According to an expedient development of the invention, both the
storage tank and also the intake duct can be arranged on a rinsing
container side wall for a space-saving arrangement. The storage tank may
also be manufactured together with the intake duct in particular composed
of a single material and/or in one piece as a standard injection molded
part.

[0020] The storage tank and the intake duct can preferably be arranged so
as to complement one another for optimal space usage on the outer side
wall of the rinsing container. To this end, the storage tank may in
particular be configured essentially L-shaped, namely with an in
particular floor-facing container segment which extends lengthways in the
depth direction and a container segment which protrudes vertically
therefrom, which can extend up to the upper edge of the rinsing container
side wall.

[0021] Free installation space is advantageously created between the two
container segments which are arranged in an L shape, in which space is
available in particular for the intake duct. In particular, its channel
segment which is routed to the common rinsing container opening can run
into the free installation space between the container segments.

[0022] The common rinsing container opening may preferably be arranged
here at an inner corner region between the two container segments of the
storage tank. The intake duct may in this way be routed past a free front
side of the horizontal container segment with its afore-cited second
channel segment in the opposite direction and run with its first
container segment to the common rinsing container opening positioned at
the inner corner region.

[0023] Other embodiments and developments of the invention are reproduced
in the subclaims. The aforecited and/or advantageous embodiments and
developments of the invention which are reproduced in the subclaims can
be used here individually or also in any combination with one another in
the inventive dishwasher and the inventive method.

[0024] The invention, its embodiments and developments as well as its
advantages are described in more detail below with the aid of drawings,
in which;

[0025] FIG. 1 shows a schematic block diagram of an advantageous exemplary
embodiment of an inventively constructed dishwasher, and

[0026] FIGS. 2 to 4 each show a sectional side view of the intake duct of
the drying facility and of the storage tank of the dishwasher in FIG. 1
with different operating states.

[0027] A dishwasher 100, in particular domestic dishwasher, having a
rinsing container 1 delimiting a rinsing chamber 2 is shown schematically
in FIG. 1. An item to be rinsed (not shown) can be arranged in the racks
3, 5, in the rinsing chamber 2 of the rinsing container 1. In the rinsing
container 1 shown, two spray apparatuses 7, 8, in particular rotating
spray arms, are arranged by way of example in different spray planes, by
way of which the item to be rinsed is subjected to rinsing fluid. A sump
11 with an only roughly sketched sieve arrangement 10 is provided in the
rinsing container base. A circulating line 9 with a circulating pump 13
arranged therein is routed away from the sump 11. The circulating line 9
is fluidically connected to the spray arms 7, 8 by way of feed lines 15.
A heating element 12 referred to as a water heater, for instance a
continuous flow heater, is arranged downstream of the circulating pump
13. The sump 11 is also connected to a drain line 17 by way of connecting
pieces, in which drain line 17 a drain pump 18 is arranged for pumping
off rinsing fluid out of the rinsing container 1. In the exemplary
embodiment, the circulating pump 13 can be coupled here to the supply
line 26' of an externally arranged storage tank 19 and to one or several
intake lines 151 for the one or several spray apparatuses 7, 8 by way of
a water switch 24, in particular a 3-way valve. A locking valve 26 is
inserted into the supply line 26'. The locking valve 26 is opened in
order to fill the storage tank 19 with washing liquor fluid and closed in
order to intermediately store fluid. The locking valve 26 is opened in
order to empty the intermediately-stored washing liquor fluid into the
rinsing chamber 2 of the wash tub 1 so that the washing liquor fluid can
flow back into the sump 11 through the line 26' solely under
gravitational effect.

[0028] The rinsing container 1 comprises a water inlet container 14 on its
left side according to FIG. 1. This is connected to the rinsing chamber 2
by way of a rinsing container opening. Furthermore it opens into the
water inlet container 14 with a fresh water feed line 16 which is coupled
to the water supply network. A water softening system (not shown) is
connected upstream of the water inlet container 14.

[0029] The rinsing container 1 comprises a so-called wash liquor store as
a storage tank 19 on its right side in FIG. 1. This may if necessary be
thermally insulated against the side wall 33 of the rinsing container 1.
Rinsing fluid can be intermediately stored in the wash liquor store 19,
which is no longer needed after running a partial program segment of a
wash cycle and can be partially or wholly used for a rinsing bath in a
wash cycle of a subsequently started dishwasher program. The wash liquor
store 19 is fluidically connected to the rinsing chamber 2 in its upper
region by way of an outlet opening 43, in particular overflow opening,
which opens into a rinsing container opening 21.

[0030] In the exemplary embodiment in FIG. 1, the storage tank 19
comprises an outlet opening 43, which opens into the rinsing container
opening 21, on its upper side. To this end, an outlet duct 41 leads from
the outlet opening 43 to the rinsing container opening 21. For the sake
of clarity in terms of the drawings, this outlet duct 41 was omitted from
FIG. 1. It is shown in detail in FIGS. 2 to 4. According to an
alternative embodiment variant it may naturally also be expedient to omit
the outlet duct 41. The outlet opening 43 of the storage tank 19 is then
expediently provided in the vicinity of the common rinsing container
opening 21. This is simultaneously connected to the intake duct 25 of a
drying facility 27 embodied as a sorption column. A fan 29 and a heating
element 31 are connected to the drying facility 27 in the intake duct 25.
The drying facility 27 contains a reversible dehydrogenizable material as
a drying material, e.g. zeolite, with which air is dried in a drying
step. To this end, an air flow charged with high humidity is siphoned off
from the rinsing chamber 2 of the rinsing container 1 by means of the fan
29 via the common rinsing container door opening 21 and is routed into
the drying facility 27 by way of the intake duct 25. The sorption
material, like zeolite, provided in the drying facility 27 absorbs
moisture from the air and the comparatively dry air is fed back into the
rinsing container 1 in the on sorption drying facility 27 by way of an
air duct 25' on the output side. The quantity of water stored in the
zeolite in the drying step can be released again in a regeneration and/or
desorption process (not shown in more detail here).

[0031] As apparent from FIG. 2, both the intake duct 25 and also the
storage tank 19 are provided on the outside side wall 33 of the rinsing
container 1. Accordingly, both the intake duct 25 and also the storage
tank 19 are in contact with the rinsing container side wall 33. The
intake duct 25 and the storage tank 19 are manufactured in one piece as a
component made of plastic material using a plastic injection molding
method. Each comprise congruent side walls, of which only the side wall
located in contact with the rinsing container side wall 33 is shown in
FIG. 2. The intake duct 25 and the storage tank 19 also comprise a
peripheral edge flange 35, which may be connected to the opposite side
wall (not shown) using welding.

[0032] As is further apparent from FIG. 2, the component assembly
consisting of intake duct 25 and storage tank 19 essentially takes up the
entire surface of the rinsing container side wall 33. The storage tank 19
and the intake duct 33 are embodied to complement one another for a
space-saving arrangement. The storage tank 19 is configured essentially
L-shaped, namely with a floor-facing elongated container segment 37 in
the depth direction x (with respect to the rinsing chamber 2) and a
container segment 39 which protrudes vertically therefrom, which extends
up to the top side of the dishwasher.

[0033] The common rinsing container opening 21 is arranged in the inner
corner region 40 between the two container segments 37 and 39. The common
rinsing container opening 21 is connected via an essentially vertically
raised, in particular integrated outlet duct 41 provided in or on the
storage tank 19, said outlet duct 41 being connected to the outlet
opening 43 of the storage tank 19 by way of an inlet segment on the input
side. This is embodied in particular as an overflow opening. The storage
chamber of the storage tank 19 opens into the outlet duct 41 via this.
The outlet opening 43 according to FIG. 2 is arranged in particular on an
upper apex of the storage tank 19 as an overflow opening and is arranged
above the common washing container opening 21 above a height difference
Δh.

[0034] Starting from the common rinsing container opening 21, a first
channel segment 45 of the intake duct 25 on the air inlet side extends
obliquely upwards to the front above a head Δhs, as a result of
which a condensation path which rises obliquely upwards is provided. The
intake duct 25 with a second channel segment 47 is then routed vertically
downwards opposite to the first channel segment 45.

[0035] For as close and compact an arrangement of the intake duct 25 and
storage tank 19 as possible, these are embodied to complement one
another. The two container segments 37, 39 bound an installation space
42, in which the channel segment 45 of the intake duct 25 runs. The
second channel segment 47 of the intake duct 25 which leads vertically
downwards is also routed frontally past a front face 49 of the lower
container segment 37 of the storage tank 19 in the depth direction x
until reaching an assembly space 51 provided below the washing container
1, in which the drying facility 27 is arranged together with the heating
element 21 and the fan 29.

[0036] As apparent from FIG. 2, a fluid droplet separator 53 is provided
in the second channel segment 47 of the intake duct 25 which comprises
tilted discharging ribs 54, 55. Fluid droplets condensed on the inner
wall of the channel segment 47 are caught with the discharging ribs 54,
55 and routed back into the channel segment 45 via a return duct 56. The
fluid droplets can be routed from there via the common rinsing container
opening 21 into the rinsing chamber 2. In particular, in the exemplary
embodiment, the return duct 56 opens here directly into the common
rinsing container opening 21.

[0037] According to FIG. 2, the intake duct 25 is connected in one piece
with the inner corner region of the storage tank 19 with its first
channel segment 45. The first channel segment 45 is connected here to the
outlet opening 23 on the lower region of the outlet duct 41.

[0038] Subsequently, the design and mode of operation of the assembly
consisting of intake duct 25 and storage tank 19 with the common rinsing
container opening 21 are described on the basis of different operating
states of the dishwasher.

[0039] The storage tank 19 in FIG. 2 is therefore shown with an
intermediately stored rinsing fluid. The fill level is limited here by a
lower edge of the outlet opening 43. The filling of the storage tank 19
can be implemented during a wash cycle during and/or after an effected
rinse-aid step. To this end, the rinse-aid fluid which is no longer
needed during and/or after the conclusion of the rinse-aid step is not
pumped off by means of the drain pump 18 of the dishwasher 100, but is
instead pumped into the storage tank 19 by means of its circulating pump
13 via the water switch 24 and via the unlocked locking valve 26 in the
feed line 26'. The locking valve 26 is then closed again. The storage
tank 19 is filled here under a pressure balance, which takes place via
the outlet opening 43, the outlet duct 41 and the common rinsing
container opening 21.

[0040] A pressure balance similarly takes place during the emptying of the
storage tank 19. In order to empty the storage tank 19, the locking valve
26 in the feed line 26' is opened and the flow path to the sump 11 is
unlocked. The intermediately stored rinsing fluid may therefore flow back
into the sump 11 under gravitational effect and be used to implement a
pre-rinse step.

[0041] According to FIG. 3, the air flow I is shown, which is siphoned off
out of the rinsing chamber 2 during a drying step at the end of the wash
cycle. The air flow I charged with high humidity is guided out of the
rinsing chamber 2 by means of the fan 29 through the rinsing chamber
opening 21 and the intake duct 25 connected thereto to the sorption
column 27, in which moisture is taken from the air flow I. Since the
dehumidified air is at the same time fed back into the rinsing chamber 2,
the air circuit during the drying step takes place at approximately
normal pressure without larger pressure fluctuations so that there is no
risk of taking in rinsing fluid which has been intermediately stored in
the storage tank 19.

[0042] FIG. 4 shows the cleaning mode in order to clean the storage
chamber of the storage tank 19. In order to implement the storage tank
cleaning, the rinsing fluid is pumped by the circulating pump 13 at high
flow speed into the storage tank 19 via the feed line 26' with an open
locking valve 26. This flows through the storage tank 19 in the manner of
an annular flow. The rinsing fluid is guided via the upper outlet opening
43 and the outlet duct 41 connected thereto to the common rinsing
container opening 21, by way of which the rinsing fluid can be
reintroduced into the rinsing chamber 2. The rinsing fluid can in this
way circulate between the rinsing chamber 2 and the storage tank 19 in a
closed circulation circuit. At the same time, the rinsing fluid in the
circulating circuit is heated to temperatures in the order of magnitude
of 70° C., as a result of which dirt particles within the storage
tank 19 can be released and discharged.

[0043] It is highly important during the cleaning mode for the fluid flow
conveyed out of the storage tank 19 via the outlet opening 43 embodied in
particular as an overflow opening and via the outlet duct 41 connected
thereto not to be able to reach the channel segment 47 via the return
duct 56 and from there to drain off to the drying facility 27. To prevent
this, a deflection rib 57 is provided downstream of the outlet duct 41 in
the merging region of the common rinsing container opening 21, with which
the fluid flow to the inner wall of the intake duct 25 is guided above
the return duct opening and cannot flow directly into the return duct 58.
A fill level 58 in the lower bottom area of the outlet duct 41 thus
ensues, whereby the return duct 56 is only filled with fluid to a minimal
degree.